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Spodumene
"Kunzite" redirects here. For the Sailor Moon character, see Shitennou. 0} at 87° | fracture = Uneven to subconchoidal | tenacity = Brittle | mohs = 6.5 - 7 | luster = Vitreous, pearly on cleavage | refractive = nα = 1.648 - 1.661 nβ = 1.655 - 1.670 nγ = 1.662 - 1.679 | opticalprop = Biaxial (+) | birefringence = δ = 0.014 - 0.018 | pleochroism = Strong in kunzite: α-purple, γ-colorless; hiddenite: α-green, γ-colorless | 2V = 54° to 69° | streak = white | gravity = 3.03-3.23 | melt = | fusibility = 3.5 | diagnostic = | solubility = insoluble | diaphaneity = | other = Tenebrescence, chatoyancy, kunzite often fluorescent under UV | references = Spodumene, Mindat.orgAnthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990). Handbook of Mineralogy. Mineral Data Publishing, Tucson, ArizonaHurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7Deer, Howie and Zussman, Rock Forming Minerals, v. 2 Chain Silicates, Wiley, 1963 pp. 92-98 }} Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, LiAl(SiO3)2, and is a source of lithium. It occurs as colorless to yellowish, purplish, or lilac kunzite (see below), yellowish-green or emerald-green hiddenite, prismatic crystals, often of great size. Single crystals of in size are reported from the Black Hills of South Dakota, United States.Robert Louis Bonewitz, 2005, Rock and Gem, London, Dorling Kindersley The normal low-temperature form α-spodumene is in the monoclinic system whereas the high-temperature β-spodumene crystallizes in the tetragonal system. The normal α-spodumene converts to β-spodumene at temperatures above 900 °C. Crystals are typically heavily striated parallel to the principal axis. Crystal faces are often etched and pitted with triangular markings. Discovery and occurrence Spodumene was first described in 1800 for an occurrence in the type locality in Utö, Södermanland, Sweden. The name is derived from the Greek spodumenos (σποδυμενος), meaning "burnt to ashes," owing to the opaque, ash-grey appearance of material refined for use in industry. Spodumene occurs in lithium-rich granite pegmatites and aplites. Associated minerals include: quartz, albite, petalite, eucryptite, lepidolite and beryl. Transparent material has long been used as a gemstone with varieties kunzite and hiddenite noted for their strong pleochroism. Source localities include Afghanistan, Australia, Brazil, Madagascar, Pakistan, Québec in Canada and North Carolina, California in the USA. Economic importance Spodumene is an important source of lithium for use in ceramics, mobile phone and automotive batteries, medicine and as a fluxing agent. Lithium is extracted from spodumene by fusing in acid. World production of lithium via spodumene is around 80,000 metric tonnes per annum, primarily from the Greenbushes pegmatite of Western Australia, and some Chinese and Chilean sources. The Talison mine in Greenbushes, Western Australia has an estimated reserve of 13 million tonnes. Some think that spodumene will become a less important source of lithium due to the emergence of alkaline brine lake sources in Chile, China and Argentina, which produce lithium chloride directly. Lithium chloride is converted to lithium carbonate and lithium hydroxide by reaction with sodium carbonate and calcium hydroxide respectively. But, pegmatite-based projects benefit from being quicker to move into production than brines, which can take 18 months to 3 years, depending on evaporation rates. With pegmatites, once a mill is built, the production of lithium carbonate is only a matter of days. Another key advantage that spodumene has over its more popular brine rivals, is the purity of the lithium carbonate it can produce. While all product used by the battery industry have to grade at least 99.5% lithium carbonate, the make up of that final 0.5% is important. If it contains higher amounts of iron, magnesium or other deleterious materials it is less attractive to end users. Gemstone varieties Hiddenite Hiddenite is a pale emerald green gem variety first reported from Alexander County, North Carolina, U. S. A. This emerald green variety of spodumene is colored by chromium, just like emeralds. Not all green spodumene is colored with chromium, which tend to have a lighter color, and therefore are not true hiddenite. Kunzite Kunzite is a pink to lilac colored gemstone, a variety of spodumene with the color coming from minor to trace amounts of manganese. Some (but not all) kunzite used for gemstones has been heated to enhance its color. It is also frequently irradiated to enhance the color. Many kunzites fade when exposed to sunlight. Kunzite was discovered in 1902, and was named after George Frederick Kunz, Tiffany & Co's chief jeweler at the time, and a noted mineralogist. It has been found in Brazil, USA, Canada, CIS, Mexico, Sweden, Western Australia, Afghanistan and Pakistan. One notable example of kunzite used in jewellery is in the Russian Palmette tiara and necklace worn by the Duchess of Gloucester.State Visit from India: HRH The Duchess of Gloucester, madhattery.com See also *List of minerals References Other sources * Kunz, George Frederick (1892) Gems and Precious Stones of North America. The Scientific Publishing Company, New York NY * Palache, C., Davidson, S. C., and Goranson, E.A. (1930) "The Hiddenite deposit in Alexander County, N.Carolina." American Mineralogist Vol 15 No. 8 p. 280 * Webster, R. (2000). Gems: Their Sources, Descriptions and Identification (5th ed.), pp. 186–190. Great Britain: Butterworth-Heinemann. * The key players in Quebec lithium, “Daily News,” The Northern Miner. August 11, 2010. External links * ** ** }} Category:Lithium minerals Category:Aluminium minerals Category:Inosilicates Category:Gemstones Category:Pyroxene group Category:Monoclinic minerals be:Спадумен de:Spodumen et:Spodumeen es:Espodumena eu:Espodumeno fa:اسپودومن fr:Spodumène hr:Spodumen it:Spodumene he:ספודומן ka:სპოდუმენი kk:Сподумен lt:Spodumenas hu:Spodumen nl:Spodumeen ja:リシア輝石 pl:Spodumen pt:Espodumena ru:Сподумен sh:Spodumen fi:Spodumeeni sv:Spodumen Category:Silicate minerals